I bought a 50 pound bag of layer feed from a local feed store for $9.95 back in October.
Earlier this week, I bought the same 50 pound bag of layer feed from the same store for $10.80.
Meantime, two weeks ago, the tag on the shelf for a 50 pound bag of black oil sunflower seed said $17.98.
Knowing that was the best price around, I decided to buy a bag. When I got the bag up to the checkout, it showed up as $20.98 on the computer. I pointed out to the checker that the tag on the shelf said it was $17.98. She did a price check and found that I was correct, so she gave me the bag for $17.98 plus tax.
Before I left, they were already in the process of changing that shelf tag to $20.98.